221221011000000 has 784 divisors, whose sum is σ = 799329673449216. Its totient is φ = 53549760000000.

The previous prime is 221221010999939. The next prime is 221221011000023. The reversal of 221221011000000 is 110122122.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 221221011000000.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 23990995390 + ... + 23991004610.

Almost surely, 2^{221221011000000} is an apocalyptic number.

221221011000000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221221011000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (399664836724608).

221221011000000 is an abundant number, since it is smaller than the sum of its proper divisors (578108662449216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221221011000000 is an frugal number, since it uses more digits than its factorization.

221221011000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10004 (or 9969 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 221221011000000 its reverse (110122122), we get a palindrome (221221121122122).

The spelling of 221221011000000 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, eleven million", and thus it is an aban number.